Flow Fill: Klaviyo Email Flows vs Postflows
Two Shopify apps, side by side: detected stores, momentum, reviews, plans, listed features and who runs each. Store counts as of Oct 13, 2026 for Flow Fill, Nov 10, 2026 for Postflows.
The short answer
- Only Flow Fill lists a free plan. Paid plans start at $19/month for Flow Fill and $89/month for Postflows.
- Flow Fill lists 4 features Postflows’s listing doesn’t mention, including Back-in-stock emails, Discounts, Price drop emails.
Head to head
Free
- · First-party revenue from your checkout
- · Flow-gap audit vs 10 standard flows
- · Gaps ranked by revenue opportunity
Pro
- · 250 builds/mo, then $0.15 each (capped)
- · Everything in Free
- · Missing-flow copy in your brand voice
Starter
Growth
Scale
Coverage counts what each App Store listing names. Every feature, checked off app by app, is in Shoplist.
See every featureFlow Fill audits your live Klaviyo flows against the 10 standard lifecycle flows and ranks the gaps by typical revenue. Write on-brand copy for any gap and edit each email as visual sections, in 18 languages and per market. Five flows — welcome, abandoned cart, browse abandonment, post-purchase, review request — push to Klaviyo as Drafts you review and switch on, never sent for you; the rest you copy across.
Shoppers want to know where their order is, and every unanswered question becomes a support ticket. Postflows turns live carrier tracking into 8 shipping events, from order placed to delivered. Each event goes straight to the email or SMS platform you already use, where it can start a flow, so brands send branded shipping updates without switching tools.
- Audit your live Klaviyo flows against the 10 standard lifecycle flows
- Build missing flows in your brand voice, pushed to Klaviyo as safe Drafts
- Visual email builder with editable AI sections, per language and market
- 10+ delivery event triggers for Klaviyo
- Branded tracking page with origin masking
- Automated WISMO ticket reduction
All the numbers
Every figure, side by side
A green dot marks the app ahead on a measured figure. Estimates, gaps and apps that leave no storefront trace never take the lead.
Adoption
| Measure |  Flow Fill |  Postflows |
|---|---|---|
| Detected stores | Not published | Not published |
| Net store change, 28 days | 0 | 0 |
| Stores added, 28 days | Not enough data | Not enough data |
| Big-brand share | Not enough data | Not enough data |
| Top store categories | Not published | Not published |
| Top store countries | Not published | Not published |
Reviews
| Measure | Flow Fill | Postflows |
|---|---|---|
| App Store rating | Not published | Not published |
| App Store reviews | Not published | Not published |
| New reviews, 28 days | Not enough data | Not enough data |
| Reviewers a year or more in | Not enough data | Not enough data |
FAQ
Flow Fill and Postflows: common questions
- Is Flow Fill or Postflows cheaper?
- Only Flow Fill lists a free plan. Paid plans start at $19/month for Flow Fill and $89/month for Postflows. Shoplist compares base prices only between monthly plans in the same currency; usage charges and annual plans vary, so check each plan’s limits.
- What features does each app list that the other doesn’t?
- Flow Fill lists 4 the others don’t mention, such as Back-in-stock emails, Discounts, Price drop emails, Tracking. Postflows lists 4 the others don’t mention, such as APIs and webhooks, Email campaigns, Follow-up emails, Templates. A feature missing from a listing may still be supported; this compares what each App Store listing says.
- Where does this comparison’s data come from?
- Shoplist crawls Shopify storefronts to detect which apps each store runs, and reads each app’s Shopify App Store listing for reviews, pricing, features and integrations. Store counts are as of Oct 13, 2026 for Flow Fill, Nov 10, 2026 for Postflows; estimated figures are labeled.
How Shoplist compares apps
Store counts come from Shoplist’s crawl of Shopify storefronts, which detects the apps each store runs; they are as of Oct 13, 2026 for Flow Fill, Nov 10, 2026 for Postflows. Reviews, ratings, plans, features and integrations come from each app’s Shopify App Store listing. 28-day figures are labeled when estimated, and a figure that is missing or estimated never decides who leads. Read the methodology.